The letter you published from PR Zeeman, concerning Stirling Moss’ remarks about Fangio taking pills in Argentina in 1955 to help overcome the heat, struck a chord.
I can do no better than refer interested parties to page 112 of Fangio – a Pirelli Album, by Stirling Moss in association with Mercedes Benz. Here it explains that Fangio’s doctor prescribed him pills to help combat the extreme thirst that plagued the Argentinian in long races. Fangio gave one to Moss before the famed 1955 Mille Miglia, and of course not only did Stirling win the race in record time, but afterwards he drove to Stuttgart for breakfast and afterwards drove home via a channel ferry, all without sleeping!
Subsequently Moss made a note in his diary about these pills, noting that they were called Dynavis, apparently manufactured in Switzerland by a company named Vister. Stirling’s father had one analysed and it contained an unidentifiable ingredient. Whatever, period medical types could probably tell us more, but I bet that they would not be allowed today.
I am, yours, etc. Paul Parker, Collier Street, London, N1